And there is rarely a need for exact physics replication.
You mention multiplayer in your tags.
Generally, in a multiplayer game, the physics and game logic is performed by one instance, which can be the server hosting the game, or one of the client that hosts the game.
Each simulation step, that authority, the server, performs logic update and physics update then send the resulting game state to all of the clients. The clients draw the scene upon reception of these events.
This way, all of the clients do not need to compute physics, they only draw. This removes a load from the clients, and it allows every one to have the same simulation. Plus it helps against cheating!
Game clients still can simulate physics for:
- estimating and predicting game behaviour
- non-game logic behaviour; e.g.: rag doll, objects destruction